Story awards for experience points

I have run a few games of D20 fantasy, and here's what I did. It worked reasonably well:

1. I set the posting rate at 3 posts a week for myself.
2. I determined the number of XP needed for everyone to get to the next level.
3. I figured out approximately how many scenes we'd need to get to the point in the story where I wanted them to level up.
4. I divided #2 by #3 to figure the XP per scene needed to level up at the right time.
5. At the end of each scene, every player who posted close to the number of times I did (~3 times a week), got the full award (i.e. #4). Every player who posted significantly less than I did (1 or 2 times a week consistently), got 75% of the reward. And every player who posted significantly more than I did (4 or more times a week), got 110% of the reward (more if they used Discord to facilitate dialogue and scene construction).

The intent was that active posters get rewarded for calling scenes, engaging with other characters and NPCs, and for doing stuff that mattered in the game. It worked reasonably well.

(But be aware, MW is full of people who sign up for a game with absolutely no intention of keeping up with the advertised posting rate. They really can't be incentivized into being more responsible with other people's time At least not in my experience.)

Given the very slow rate of PvP combat I'd like to be able to reward players for things other than defeating monsters, such as playing out a courtroom scene. I want to create a set of "story award" guidelines for how to hand out experience points in my heavily houseruled D&D 3.5e campaign. I realize I'm free to create anything I like, but I'd appreciate learning from the experience of other 3.5e players and DMs. Or from any system that uses experience points in the hundreds to thousands range, really.

Do any of the rest of you give XP for accomplishing story goals, and what sort of guidelines did you use?

Do you give "roleplaying awards" for individual players or do you view that as unfair to people who are less articulate?

If you use a "milestone" system for raising levels, what sort of guidelines do you use for that? I personally prefer something more XP-for-roll/role-playing" than milestones but I'm prepared to learn from those who do use them.

When I was using 3.5 and derivatives, I estimated the XP for diplomacy by the encounter guidelines. Whether you're using diplomacy to overcome a dragon, or fighting it, you get the same rewards.

That lead to quite quick levelling up in my groups, but I'm fine with that.